Question: What do the following two equations represent? $3x+y = 3$ $-5x+15y = -4$
Putting the first equation in $y = mx + b$ form gives: $3x+y = 3$ $y = -3x+3$ Putting the second equation in $y = mx + b$ form gives: $-5x+15y = -4$ $15y = 5x-4$ $y = \dfrac{1}{3}x - \dfrac{4}{15}$ The slopes are negative inverses of each other, so the lines are perpendicular.